Field of the Disclosure
Embodiments of the present invention relate to an organic light emitting display device, and more particularly, to a white organic light emitting display device for emitting a white light and an organic light emitting display apparatus using the same.
Discussion of the Related Art
An organic light emitting display device is provided in such a structure in which a light emitting layer is formed between a cathode for injecting an electron and an anode for injecting a hole. When the electron generated in the cathode and the hole generated in the anode are injected into the inside of the light emitting layer, an exciton is produced by recombination of the electron and hole. Then, when the exciton falls to a ground state from an excited state, the organic light emitting display device emits light.
The organic light emitting display device may be applied as a thin-profile light source of a liquid crystal display device or display device as well as lighting. Especially, the organic light emitting diode for emitting a white light may be combined with a color filter, and may be applied to a full-color display device.
A white organic light emitting display device for emitting a white light may be formed in a structure including two light emitting layers with complementary colors. In this structure, when the white light transmits through the color filter, there is a difference between a peak wavelength region for each light emitting layer and a transmission region of the color filter, whereby a color reproduction range becomes small, that is, it is difficult to realize a desired color reproduction ratio.
For example, in case of an organic light emitting display device including blue and yellow emitting layers for an emission of white light, an emission peak wavelength is formed in a blue wavelength region and a yellow wavelength region, to thereby emit a white light. However, if the white light transmits through red, green and blue color filters, a transmittance of the blue wavelength region is relatively lower than a transmittance of a red or green wavelength region, thereby causing a low emission efficiency and a low reproduction ratio. Also, the blue emitting layer is formed of a fluorescent material and the yellow emitting layer is formed of a phosphorescent material. In this case, an emission efficiency of the yellow emitting layer of the phosphorescent material is relatively higher than an emission efficiency of the blue emitting layer of the fluorescent material, whereby an emission efficiency and a color reproduction ratio are lowered due to a difference between the efficiency of the yellow emitting layer of the phosphorescent material and the efficiency of the blue emitting layer of the fluorescent material.
The organic light emitting display device of the related art is disclosed in the Korean Patent Application Publication No. 10-2011-0035048.